A rolling bearing with a rotation sensor is sometimes used as a bearing for supporting a rotary shaft in various types of rotary equipment, in order to detect its rotational speed (number of revolutions). This rolling bearing with a rotation sensor has an annular magnetic encoder alternately magnetized in opposite polarities in its circumferential direction and mounted on one of the inner and outer races which is rotatable. A magnetic sensor(s) configured to detect the changes in the magnetic flux when the magnetic encoder is rotated is mounted within a sensor housing mounted on the other one of the races, which is stationary, to detect the rotation of the rotating race. A circuit board for processing the output of the magnetic sensor is also often mounted in the sensor housing.
In many cases, such a sensor housing for a rolling bearing with a rotation sensor is made of a resin, and mounted on the stationary race through an outer ring made of a metal (see, JP 2008-111480).
JP 2008-111480 discloses a sensor housing which is made of a polymer alloy obtained by mixing polyphenylene sulfide (PPS) with polyamide (PA) and polyimide (PI). It is also disclosed therein that the use of this polymer alloy for forming the sensor housing is effective in reducing the creep of the sensor housing due to temperature change.